SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '911ae9cbbda9179969d3c218b418169cb747db878d23ed6a165126195e9eb0b7' 
  AND token = 'vsyxHJPV+NtXEwbePo55zvVKb5QfTZ5X+79lLoIcUSg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00059

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}